1. Field of the Invention
The present invention relates to electronic equipment, and more particularly to a portable information terminal, which a user carries to retrieve, read out, input and the like information.
2. Description of the Related Art
In general, personal information terminals or portable information terminals called personal digital assistants (PDA) have become popular in recent years. The portable information terminal (hereinafter referred to as xe2x80x9ca PDAxe2x80x9d) comprises a keyboard, a display such as a liquid crystal display panel, a central processing unit (CPU) and a large-capacity semiconductor memory. Basically, it is a small-sized information terminal to be actuated by a built-in battery. High performance CPUs have been available at a relatively inexpensive cost owing to the progress of a semiconductor integration technique, and further, a large-capacity semiconductor memory (hereinafter simply referred to a memory) has been available at an inexpensive cost, thereby achieving a small-sized memory of high performance. A remarkably large quantity of data required for business operations can be stored in the memory. Therefore, the necessary data (i.e., the information) can be read out of a personal computer (PC) and stored in the memory of the PDA. A user brings the PDA to a customer site and retrieves the data stored in the PDA as required.
The data stored in the memory in the above-described PDA can comprise numerous product names, product numbers, prices, delivery dates, inventories, etc. Although the data can be carried in the form of a document, e.g., a catalog or a price list, the document is bulky and can be difficult to update the data, which is changed from moment to moment. In contrast, the use of the PDA enables enormous data not only to be integrated into the small-sized memory but also to be updated with ease, thereby making it possible to make access to the latest data all the time. Moreover, any data processing after the business discussion can be speedily performed with ease by inputting the result of the business discussion into the PDA. Additionally, the PDA can be used in place of name cards by inputting numerous company names, names in charge, contact destinations (such as telephone numbers) and other relevant information about the customers, and further, can be used for the schedule management of the user.
The prior art in the above-described technical field is disclosed in Japanese Laid-Open Patent Application Heisei 10-164195 entitled xe2x80x9cPortable Information Equipmentxe2x80x9d and Japanese Laid-Open Patent Application Heisei 9-6950 entitled xe2x80x9cName Card Reader.xe2x80x9d
The PDA is required to be reduced in size and weight as possible, to have the sufficient storage capacity of a memory, and to speedily retrieve the necessary data (i.e., information) therefrom with ease. In order to enhance the above-described performance of the PDA, there has been proposed a structure in which a part of the keyboard is movable or slidable with respect to another portion of the PDA, such as the display.
However, the prior art discloses a movable unit comprising a movable structure unit and an electrically connecting unit for transmitting or receiving a signal between the movable unit and the main unit. Therefore, it is necessary to provide spaces for both of the movable structure unit and the electrically connecting unit, thereby making miniaturization difficult and increasing manufacturing costs. Moreover, the electrically connecting unit (i.e., a cable) in an inoperative state (for example, when the PDA is not used or contained) becomes cumbersome, and requires excess storage space.
An aspect of the present invention is to provide a portable information terminal in which the processing of an electrically connecting unit (i.e., a cable) can be facilitated in a small space.
To solve the above mentioned problem, a portable information terminal comprises a first case unit comprising a display, a second case unit comprising an operation key and a resilient cable member for resiliently retaining said second case unit together with said first, and the second case unit are slidable against the first case unit. The resilient cable member has a spiral winding. Also, the resilient cable member is wound around a center shaft. The portable information terminal of the present invention further comprises a flat circuit board (FPC) that is disposed on both sides of the resilient cable member. Both ends of the resilient cable member are connected to connectors disposed in the first case unit and the second case unit, respectively. The portable information terminal further may comprise a flat circuit board (FPC) that is disposed on either side of the resilient cable member. The portable information terminal further comprises a protecting film that is provided at the other surface of the resilient cable member. Both ends of the resilient cable member are connected to connectors disposed in the first case unit and the second case unit, respectively. The operation key is preferably covered with the first case unit when the portable information terminal is not used. Further, the portable information terminal comprises latching means for latching the second case unit to the first case unit when the second case unit is withdrawn. The portable information terminal of the present invention further comprises a judging means for judging whether or not the second case unit is drawn and a controlling means for controlling a power switch for the portable information terminal based on a result of the judging means. The power switch is automatically turned on when the second case unit is withdrawn. The second case unit preferably slides along guide rails provided in the first case unit. The portable information terminal may be a portable telephone.
In another embodiment of the present invention, the operation key is stored within the first case unit when the portable information terminal is not used. The portable information terminal further comprises a latch that latches the second case unit to the first case unit when the second case unit is pulled from within the first case unit. The portable information terminal further comprises a sensor that determines whether or not the second case unit is pulled from the first case unit, and a controller that activates a power switch for the portable information terminal based on a result of the sensor. The power switch is automatically turned on when the second case unit is pulled from the first case unit. The second case unit slides along guide rails disposed in the first case unit.
The portable information terminal according to the present invention can produce prominent effects in practical use, as described below. First of all, the main unit and the operating unit, which slide with respect to each other in accordance with the use state or the idle (contained) state, are mechanically connected by the use of the resilient cable member having a spiral winding. This provides a portable information terminal with the reduced number of use parts at the low cost in the small size and is excellent in operability.
Furthermore, the extra cable is wound around the center shaft by the use of the resilient cable member comprising the resilient member in which the cable has a spiral winding, thus coping with a play (i.e., an extra portion) of the cable in the idle (contained) state within the small space.